3,744 research outputs found
Understanding the relevance of national culture in international business research: a quantitative analysis
This review is a comprehensive quantitative analysis of the International Business literature whose focus is on national culture. The analysis relies on a broad range of bibliometric techniques as productivity rankings, citation analysis (individual and cumulative), study of collaborative research patterns, and analysis of the knowledge base. It provides insights on (I) faculty and institutional research productivity and performance; (II) articles, institutions, and scholars’ influence in the contents of the field and its research agenda; and (III) national and international collaborative research trends. The study also explores the body of literature that has exerted the greatest impact on the researched set of selected articles.info:eu-repo/semantics/publishedVersio
Patterns of genetic diversity in three plant lineages endemic to the Cape Verde Islands
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. The file attached is the published version of the article
Cabo Verde’s Poaceae Flora: A Reservoir of Crop Wild Relatives Diversity for Crop Improvement
Africa is home to important centers of origin and diversity of crop wild relatives (CWR), including many species adapted to adverse agroecological conditions, namely drought and poor soils. Plant genetic resources from Cabo Verde Islands have been poorly explored for their potential to supplement the genetic pool of cultivated species. In this paper we identify Cabo Verde's CWR from the Poaceae family and provide a checklist of priority CWR taxa, highlighting those of particular conservation concern and the areas which should be the focus of the most intensive conservation efforts in these islands. Our results revealed that Cabo Verde archipelago is an important center of CWR diversity of West African crop millets, namely fonio (e.g., white fonio, Digitaria exilis, and black fonio, Digitaria iburua) and other African millets [e.g., pearl millet (Cenchrus americanus = Pennisetum glaucum), teff millet (Eragrostis tef), finger millet (Eleusine coracana), barnyard millet (Echinochloa colona), proso millet (Panicum miliaceum), and foxtail millet (Setaria italica)], which represent a diverse group of cereal crops, and important components in agriculture and food security of this country. Also, hotspot areas of diversity for in situ conservation were identified in Cabo Verde, as well as several populations occurring under extreme habitats conditions that are well adapted to drylands and poor soils. The evaluation of their potential for new ecologically important adaptive characteristics associated with tolerance to abiotic stresses is discussed. The survey of international Germplasm Banks revealed that very few accessions from Cabo Verde are conserved, contributing to the loss of genetic diversity of plant genetic resources in this archipelago. Particularly, the diversity of millets and the associated indigenous knowledge are critical for the food security and cultural identity of many poor farmers in Cabo Verde.info:eu-repo/semantics/publishedVersio
Hyperprolinemia as a clue in the diagnosis of a patient with a psychiatric disorder
Background: Over the last few years, microdeletions of the 22q11.2 region responsible for DiGeorge syndrome, or velocardiofacial syndrome, have been increasingly related to neuropsychiatric disorders including schizophrenia and bipolar disorders. These signs seem to be related to certain genes located in the
hemideleted region as the proline dehydrogenase (PRODH) and the catecholo-methyltransferase (COMT) genes. The PRODH or proline oxidase deficiency is responsible for hyperprolinemia type 1 (HPI) also causing psychiatric manifestations.
Case Report: We describe a 17 year old boy with previous mild psychomotor and speech delay, mild cognitive impairment, and obsessive behaviours who started his adolescent psychiatric care presenting irritablemood and aggressive behaviour with schizophrenia symptoms that scored a “severely ill” level PANSS assessment. Symptoms got worse when he was treated with valproic acid and plasma aminoacids showing increase in alanine and proline, suggested a mitochondrial involvement of the proline metabolic pathway.
Results: Mild dysmorphia suggested a possible 22q11.2 deletion genetically confirmed involving both the PRODH and COMT regions. HPI that can present with psychiatric features is however a recessive disorder and therefore the symptoms could not be solely explained by this genetic deletion. Additional
investigations also showed disclosed a p.L289m (c.1865 T > A) mutation in the PRODH gene.
Discussion: We believe that the association of this mutation together with the 22q11.2 deletion would lead to a decrease of functional protein. Although it may be difficult to diagnosis chromosomal abnormalities in patients with no clear malformations and mild dysmorphic features as in this patient we emphasize
need to investigate the aetiology in patients with psychiatric symptoms, especially if they have other systemic manifestations such as developmental delay or psychotic symptoms, as it may be important in the management of the patients
Entangled effects of allelic and clonal (genotypic) richness in the resistance and resilience of experimental populations of the seagrass Zostera noltii to diatom invasion
Background - The relationship between species diversity and components of ecosystem stability has been extensively studied, whilst the influence of the genetic component of biodiversity remains poorly understood. Here we manipulated both genotypic and allelic richness of the seagrass Zostera noltii, in order to explore their respective influences on the resistance of the experimental population to stress. Thus far intra-specific diversity was seldom taken into account in management plans, and restoration actions showed very low success. Information is therefore needed to understand the factors affecting resistance and resilience of populations.
Results
Our results show a positive influence of both allelic and genotypic richness on the resistance of meadows to environmental perturbations. They also show that at the low genotypic (i.e. clonal) richness levels used in prior experimental approaches, the effects of genotypic and allelic richness could not be disentangled and allelic richness was a likely hidden treatment explaining at least part of the effects hitherto attributed to genotypic richness.
Conclusions
Altogether, these results emphasize the need to acknowledge and take into account the interdependency of both genotypic and allelic richness in experimental designs attempting to estimate their importance alone or in combination. A positive influence of allelic richness on resistance to perturbations, and of allelic richness combined with genotypic richness on the recovery (resilience) of the experimental populations is supported by differential mortality. These results, on the key species structuring of one of the most threatened coastal ecosystem worldwide, seagrass meadows, support the need to better take into account the distinct compartments of clonal and genetic diversity in management strategies, and in possible restoration plans in the future.Peer Reviewe
Histone Epigenetic Signatures in Embryonic Limb Interdigital Cells Fated to Die
During limb formation in vertebrates with free digits, the interdigital mesoderm is eliminated by a massive degeneration process that involves apoptosis and cell senescence. The degradation process is preceded by intense DNA damage in zones located close to methylated DNA, accompanied by the activation of the DNA repair response. In this study, we show that trimethylated histone 3 (H3K4me3, H3K9me3, and H3K27me3) overlaps with zones positive for 5mC in the nuclei of interdigital cells. This pattern contrasts with the widespread distribution of acetylated histones (H3K9ac and H4ac) and the histone variant H3.3 throughout the nucleoplasm. Consistent with the intense labeling of acetylated histones, the histone deacetylase genes Hdac1, Hdac2, Hdac3, and Hdac8, and at a more reduced level, Hdac10, are expressed in the interdigits. Furthermore, local treatments with the histone deacetylase inhibitor trichostatin A, which promotes an open chromatin state, induces massive cell death and transcriptional changes reminiscent of, but preceding, the physiological process of interdigit remodeling. Together, these findings suggest that the epigenetic profile of the interdigital mesoderm contributes to the sensitivity to DNA damage that precedes apoptosis during tissue regression
Sargassum muticum and Osmundea pinnatifida food-grade extracts with antioxidant activity for novel functional foods
Antibiotic resistance in wastewater: Occurrence and fate ofEnterobacteriaceaeproducers of Class A and Class C β-lactamases
Antibiotics have been intensively used over the last decades in human and animal therapy and livestock, resulting in serious environmental and public health problems, namely due to the antibiotic residues concentration in wastewaters and to the development of antibiotic-resistant bacteria. This study aimed to access the contribution of some anthropological activities, namely urban household, hospital and a wastewater treatment plant, to the spread of antibiotic resistances in the treated wastewater released into the Mondego River, Coimbra, Portugal. Six sampling sites were selected in the wastewater network and in the river. The ampicillin-resistant Enterobacteriaceae of the water samples were enumerated, isolated and phenotypically characterized in relation to their resistance profile to 13 antibiotics. Some isolates were identified into species level and investigated for the presence of class A and class C -lactamases. Results revealed high frequency of resistance to the -lactam group, cefoxitin (53.5%), amoxicillin/clavulanic acid combination (43.5%), cefotaxime (22.7%), aztreonam (21.3) cefpirome (19.2%), ceftazidime (16.2%) and to the non--lactam group, trimethoprim/sulfamethoxazol (21.1%), tetracycline (18.2%), followed by ciprofloxacin (14.1%). The hospital effluent showed the higher rates of resistance to all antibiotic, except two (chloramphenicol and gentamicin). Similarly, higher resistance rates were detected in the wastewater treatment plant (WWTP) effluent compared with the untreated affluent. Regarding the multidrug resistance, the highest incidence was recorded in the hospital sewage and the lowest in the urban waste. The majority of the isolates altogether are potentially extended-spectrum -lactamases positive (ESBL(+)) (51.9%), followed by AmpC(+) (44.4%) and ESBL(+)/AmpC(+) (35.2%). The most prevalent genes among the potential ESBL producers were blaOXA (33.3%), blaTEM (24.1%) and blaCTX-M (5.6%) and among the AmpC producers were blaEBC (38.9%), blaFOX (1.9%) and blaCIT (1.9%). In conclusion, the hospital and the WWTP activities revealed to have the highest contribution to the spread of multidrug resistant bacteria in the study area. Such data is important for future management of the environmental and public health risk of these contaminants. This is the first embracing study in the water network of Coimbra region on the dissemination of antibiotic resistance determinants. Moreover, it is also the first report with the simultaneous detection of multiresistant bacteria producers of AmpC and ESBLs -lactamases in aquatic systems in Portugal.info:eu-repo/semantics/publishedVersio
Diastereo-selectivity in diels–alder cycloadditions of erythrose benzylidene-acetal 1,3-Butadienes with maleimides
Maleimides were combined with D-erythrose benzylidene-acetal 1,3-butadienes 1 and 2 to study the facial selectivity of the Diels-Alder cycloadditions. The selectivity was found to be from moderate to good. The reaction diastereotopicity can be reversed with the temperature. Simultaneous coordination of diene 1, having a free hydroxyl group, and maleimide 3 to a chiral bimetallic Lewis acid catalyst (LACASA-DA reaction) occurs with complete diastereo-control to give a single adduct, using an extra chiral inductor either R- or S-BINOL.Thanks are due to FCT for project funding PTDC/QUI/67407/2006 and FCT and FEDER for funding the NMR spectrometer Bruker Avance III 400 as part of the National NMR Network. V. C. M. D. also thanks for PhD grant (SFRH/BD/61290/2009)
A Biologia e a Matemática vistas com as mãos e com os olhos através do croché
O croché, a arte de puxar laçadas de fio através de loops com a ajuda de uma agulha em gancho, é uma técnica muito promissora no desenvolvimento de competências e na transmissão de conceitos. Por um lado, permite o aperfeiçoamento da motricidade fina, bem como da flexibilidade de raciocínio e do pensamento lógico. Por outro, viabiliza a construção de modelos tridimensionais manipuláveis, representativos de conceitos em diversas áreas científicas como a Biologia e a Matemática. Talvez o caso mais icónico seja o da criação de modelos físicos de espaços hiperbólicos, avançado pela primeira vez por Daina Taimina, em 1997 (1). É, até hoje, a única técnica capaz de representar, a três dimensões, as propriedades da geometria hiperbólica patente no mundo vivo, por exemplo, no padrão de crescimento dos corais e de diversas plantas. Foi, inspirando-se neste trabalho, que o projecto STOL – Science Through Our Lives, recriou um recife de corais em croché denominado “Ponto a Ponto Enche a Ciência o Espaço” (2), numa lógica WIP (Work in Progress), que já pôde ser visto em diversos locais do país e que está associado a uma oficina de carácter hands on.
Mais recentemente, a equipa STOL produziu, em croché, modelos de plantas – fractal, por exemplo fetos, que estão a ser usados para transmitir conceitos matemáticos de geometria fractal e auto-semelhança, na oficina ’Matemática das Plantas’ proposta pelo Museu Nacional de História Natural e da Ciência da Universidade de Lisboa (MUHNAC) que, a partir do seu património único (3) no centro da cidade, integra estratégias participativas na sua oferta educativa. Recorrendo a uma pedagogia baseada em hands on, surge o questionamento: o que dizem estes crochés curiosos? As metodologias de Aprendizagem Activa no Ensino das Ciências – IBSE (Inquiry Based Science Education) - explicam porque é importante questionar (4). A partir de estruturas naturais do jardim e outros objectos como os produzidos no âmbito desta parceria feliz entre o STOL e o MUHNAC, quer-se levar o participante a questionar aspectos da Matemática e da Biologia.info:eu-repo/semantics/publishedVersio
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